I'm dual booting XP and Kubuntu. I wanted to boot to my existing raw scsi XP partition inside Kubuntu, not a virtual XP instance. I accidentally booted Kubuntu inside itself. I know this is a big mistake, so I interrupted the VM, which saved the state and closed. I rebooted the host and now I can't load the Kubuntu partition at boot time. I get a maintenance shell and the Kubuntu partition is read-only. I am able to boot XP as usual. I removed the HDD and tried to mount it on another computer as an external drive and neither partition (XP or Kubuntu) will be recognized, it just appears to be one device that still mounts and appears empty. From the maintenance shell I can see all the files are still on the Kubuntu partition.

How can I undo what I did when I accidentally booted Kubuntu inside itself? Is it a matter of unlocking some files somewhere? how can I do that on a RO filesystem?
Thanks!